To reduce a weight of a structural body having strong rigidity and high precision used for building material, construction, vehicle, ship and other structure.

In a member consisting of plural deck plates or angle steels crossing/arraying in at least two stage stacked and steel plates on the top and bottom, each point, at which the angle steels 1, 2 crossed/arrayed in stages, is spot welded, further, the steel plates 3, 4 arranged on the top/bottom of stage stacked angle steels are joined by resistance welding. By this method, based on a honeycomb structure known as a high rigidity light weight structural body made of thin thickness members, by use of a thin sheet member for structural body constituting elements and joining of members with resistance welding suitable for welding of thin sheet, the light weight structural body to realize strong rigidity and high precision is made possible.